//=================================================================================================
// Copyright (c) 2013, Johannes Meyer, TU Darmstadt
// All rights reserved.

// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//     * Redistributions of source code must retain the above copyright
//       notice, this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above copyright
//       notice, this list of conditions and the following disclaimer in the
//       documentation and/or other materials provided with the distribution.
//     * Neither the name of the Flight Systems and Automatic Control group,
//       TU Darmstadt, nor the names of its contributors may be used to
//       endorse or promote products derived from this software without
//       specific prior written permission.

// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE FOR ANY
// DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
// ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//=================================================================================================

#include <hector_pose_estimation/filter/ekf.h>

namespace hector_pose_estimation {
namespace filter {

EKF::EKF()
{}

EKF::~EKF()
{}

bool EKF::init(PoseEstimation &estimator)
{
  x_pred.resize(state_.getDimension());
  x_pred.setZero();
  A.resize(state_.getDimension(), state_.getDimension());
  A.setZero();
  Q.resize(state_.getDimension());
  Q.setZero();
  return true;
}

bool EKF::doPredict(double dt) {
  ROS_DEBUG("EKF prediction (dt = %f):", dt);

  ROS_DEBUG_STREAM("A      = [" << A << "]");
  ROS_DEBUG_STREAM("Q      = [" << Q << "]");

  state().P() = A * state().P().selfadjointView<Upper>() * A.transpose() + Q;
  state().x() = x_pred;

  ROS_DEBUG_STREAM("x_pred = [" << state().getVector().transpose() << "]");
  ROS_DEBUG_STREAM("P_pred = [" << state().getCovariance() << "]");

  Filter::doPredict(dt);
  return true;
}

} // namespace filter
} // namespace hector_pose_estimation
